Purpose
To estimate the prevalence of visual impairment in elderly Europeans, as a function of geographical area and time period.
Methods
The E3 consortium comprises 15 population-based studies, performed in 10 European countries from 1991 to 2012. The study population includes 103,677 participants, 55 years or older, with visual acuity measurements. Following WHO guidelines, visual impairment was classified as presenting visual acuity <20/60. Non-refractive visual impairment was classified as best-corrected visual acuity <20/60. European countries were stratified into three areas, i.e., Northern, Western and Southern Europe, according to the United Nations geoscheme. Early and late time periods were separated by the median (year 2006). Each study provided numbers of subjects affected by visual impairment, according to gender and 5-year age groups. Random-effect meta-analysis models were performed to estimate prevalence rates across studies. Age-standardized prevalence rates were obtained in two steps: firstly, prevalence rates were estimated in each age group, and secondly, an age-standardization was performed according to the European Standard Population 2010.
Results
9 studies had data on presenting visual acuity (76,141 subjects) and 13 studies on best-corrected visual acuity (57,508 subjects). Prevalence of the two visual impairment endpoints did not vary significantly by geographical area. By contrast, both visual impairment endpoints decreased over time. Age-standardized prevalence rates of presenting visual impairment decreased from 4.88 % (95 % confidence interval (CI): 2.21-7.58) before 2006 to 2.27 % (95 % CI: 0.18-4.66) after 2006. Similarly, the prevalence of non-refractive visual impairment decreased from 2.21 % (95 % CI: 1.26-3.13) before 2006 to 0.74 % (95 % CI: 0.33-1.09) after 2006 .
Conclusions
The prevalence of visual impairment in elderly Europeans has decreased in recent years. This may be partly due to increased availability of cataract surgery and treatments for age-related macular degeneration. Uncorrected refractive errors remain responsible for more than half of the cases of visual impairment.
Keywords: 754 visual acuity •
463 clinical (human) or epidemiologic studies: prevalence/incidence